Results 171 to 180 of about 2,355 (221)

Diagenetic alteration in black shales

Journal of the Geological Society, 1980
To most field geologists 'black shales' are dark, fissile sedimentary rocks which are rich in both carbon and sulphur. The property of fissility probably develops only in sediments deposited from anoxic bottom waters. Carbon and sulphur-rich sediments are formed wherever relatively organic-rich material accumulates at such a rate that intensive ...
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Metalliferous Black Shales

1991
Abstract Black shales are frequently repositories for valuable metal constituents and represent a record of past anoxic water conditions. These metalliferous, carbon-rich units also record geochemical interactions of carbon, iron, sulfur, oxygen, and often phosphorus.
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Model for transgressive black shales?

Geology, 1991
Many black shales in thick epicontinental basinal successions formed beneath an oxygen-restricted puddle of deep water. Other black shales formed during rapid transgression when basinal deposition expanded to cover basin-margin areas normally characterized by shallow-water deposition.
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Au-Cu Black Shale Formations

Earth Science Frontiers, 2007
Abstract The results of the generalization of lithologic-facial and paleogeographic reconstructions and genetic formational analysis of the various metalliferous high-carbonaceous Phanerozoic sedimentary complexes are presented and systematized. The factors predetermining the origin of ore concentrations of gold and copper are specified.
V.I. STAROSTIN, O.V. YAPASKURT
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Trace elements in black and oil shales

Solid Fuel Chemistry, 2007
Data on the abundance of trace elements in oil and black shales, as well as and the average concentrations of trace elements in these caustobioliths, are considered. In general, oil shales are enriched in Li, Be, B, Rb, Ta, and Se and depleted in Mo, Re, Ag, Au, V, Th, Cu, Hg (and, perhaps, W, As, and U) relative to black shales.
M. Ya. Shpirt, S. A. Punanova, Yu. A. Strizhakova   +2 more
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Environments of Origin of Black Shales

AAPG Bulletin, 1939
ABSTRACT Explanations of origin are reviewed and environments in which black muds are in process of deposition are considered. The causes of blackness are examined and attention is given to diagenetic processes that take place in black muds.
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The Black Shale of Southwestern Virginia

The Journal of Geology, 1924
Conclusions as to the age and correlation of the black shale in several sections measured in southwestern Virginia are presented by the writer. There are recognized in this area the Genesee shale, Portage shale, and Chemung formation, of Devonian age, and a black shale correlated with the Chattanooga shale but here called the Big Stone Gap shale, of ...
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Black Shales

PALAIOS, 1995
Walter Etter, Paul B. Wignall
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Growth of sulphides in black shales.

1959
Sulphides can be divided into two major groups, those which are of hydrothermal origin and those which are of sedimentary origin. The sulphides of sedimentary origin are found in greatest abundance in bituminous rocks and it is these sulphides that have been investigated in the present work. A study of the sedimentary sulphides is of special importance
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Biological leaching of shales: black shale and oil shale

2014
http://www.ester.ee/record=b1053457~S1 ...
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